(19)
(11) EP 0 184 750 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
13.07.1988 Bulletin 1988/28

(43) Date of publication A2:
18.06.1986 Bulletin 1986/25

(21) Application number: 85115270

(22) Date of filing: 02.12.1985
(84) Designated Contracting States:
DE NL

(30) Priority: 03.12.1984 JP 25531784

(71) Applicant: HITACHI, LTD.
 ()

(72) Inventors:
  • Ito, Tetsuo
     ()
  • Sasaki, Hiroshi
     ()
  • Sato, Yoshio
     ()
  • Shimada, Satoshi
     ()
  • Miyamoto, Norifumi
     ()
  • Tsuboi, Nobuyoshi
     ()
  • Nihei, Hideki
     ()
  • Koyanagi, Hiroaki
     ()

   


(54) Optical recording and reproducing device


(57) A laser light flux is divided and synthesized so that its light intensity distribution is changed from a Gaussian distribution to a non-Gaussian distribution. When a laser light flux (L0) having a Gaussian distribution is irradiated onto a dividing prism (1), it is divided into a left part (11) and a right part (12) which are refracted right and left invensely from each other. When the right and left parts (I1, 12) are incident on a synthesizing prism, they are refracted again and travel to be overlapped with each other on a recording medium. The light intensity distribution on a segment (dd') at the apex of the synthesizing prism is weaker at the central part and stronger at the peripheral part. This is because the light fluxes resulting from the division are inverted in their position so that the central part of the Gaussian distribution is separated left and right while the peripheral part with a weaker light intensity is centered.






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